COLUMBUS – Three drones have flown into Ohio prisons this year, some dropping drugs, but no law prohibits the unmanned aircraft from flying over prisons and no technology easily prevents it.

That could make stopping the next drone drug drop a challenge.

“We’re in this new era of unmanned flight, and we’re scrambling trying to deal with all the ramifications, many of which were unanticipated,” said Michael Braasch, a professor of electrical engineering at Ohio University who has researched drones for 15 years.

Last month, someone flew a drone with heroin, marijuana and tobacco into a recreation yard at Mansfield Correctional Institution, inciting a fight among several inmates as they scrambled for the drugs. The Ohio State Highway Patrol is investigating who sent the drone, but it wasn’t the first to fly into Ohio’s prisons.

On Jan. 4, someone flew a toy drone into Franklin Medical Center in Columbus, where an inmate found it and turned it in. No drugs were attached to the unmanned aircraft. On May 31, a prison sergeant found a drone with a package of marijuana attached while conducting a fence check at the North Central Correctional Institution in Marion.

Unlike airplanes, unmanned drones don’t have limits on how low they can fly or, in many instances, where they can fly, Braasch said.

The Federal Aviation Administration recommends flying lower than 400 feet and keeping drones in sight, but that’s not a requirement. The FAA also prohibits drone flight in certain areas, such as flying over stadiums or racetracks during events and most recently, flying over wildfires, which was a problem in California. But there’s no restriction for prisons or jails.

“The act of flying an aircraft, manned or unmanned, over a facility is not, in itself, a crime,” patrol Lt. Craig Cvetan confirmed.

However, drone pilots can get in trouble with the FAA for dropping items from the air, carrying drugs on an aircraft and reckless operation. People who sneak drugs into prison — by flight or otherwise — face felonies for breaking state law. But penalties are rare; the FAA has opened 20 cases for misuse of drones in recent years and only five have been resolved.

U.S. Sen. Chuck Schumer, D-New York, announced Wednesday that he wants more limits on drones and soon. He proposed legislation that would force all drone manufacturers to equip their unmanned aircraft with technology that prevents them from flying in certain areas such as airports. The senator cited Ohio’s recent drug drops as examples of how drones can be dangerous, but his office did not clarify whether prisons would be off limits.

Meanwhile, Ohio prison officials created a task force to detect drones and prevent from from dropping drugs into their facilities, spokesman Scott Flowers said. The group has not yet met, and Flowers had no details on what they would consider.

Officials could try to jam the drones’ signals electronically or knock them out of the air with sound waves, but those options are relatively untested and could hurt other electronics in the area, Braasch said. Guards could always shoot them out of the sky, Braasch joked. Some businesses even sell special ammunition to do it.

But Flowers said that wasn’t an option: “(F)lying an (unmanned aerial vehicle) over a prison is not justification to discharging a firearm.”